This assignment provides both a review of the anatomy and function of the posterior cruciate ligament (PCL), and an overview of diagnostic methods and conservative treatment options for patients with isolated PCL injuries.The PCL functions as a primary restraint to posterior tibial translation. PCL injuries are relatively infrequent. Approximately 45 % of the injuries are caused by road accidents and 40 % occur during sports. The most common injury mechanism of isolated PCL ruptures, is a direct blow to the anterior part of the proximal tibia in the flexed knee. Since the blow often is anteromedial or anterolateral, and thus injures other knee structures as well, isolated PCL ruptures are rarely seen. The posterior drawer test is the most accurate clinical test for diagnosing PCL ruptures. If the clinical examination does not verify the injury, an MRI is usually clarifying.Conservative rehabilitation is often preferred, but there are no guidelines on how to proceed. The rehabilitation has to be individualized, and is often divided into three phases: immobilisation in full extension; muscle strengthening; and sport specific training. Conservative rehabilitation has been the treatment of choice for injuries where the tibial displacement in relation to the femur is less than 11 mm. For the injuries with more displacement, there still lack consensus whether conservative or surgical treatment should be preferred. Reviewing the literature, the results and the prognosis of isolated PCL ruptures treated conservatively do vary. Some function well, others end up having pain, especially anterior knee pain during loading.